s390/crypto: add s390 platform specific aes gcm support. (bf7fa038) · Commits · e / devices / android_kernel_fairphone_FP5

arch/s390/crypto/aes_s390.c

+293 −3

Original line number	Diff line number	Diff line
		@@ -4,9 +4,11 @@
		* s390 implementation of the AES Cipher Algorithm.
		*
		* s390 Version:
		* Copyright IBM Corp. 2005, 2007
		* Copyright IBM Corp. 2005, 2017
		* Author(s): Jan Glauber (jang@de.ibm.com)
		* Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
		* Patrick Steuer <patrick.steuer@de.ibm.com>
		* Harald Freudenberger <freude@de.ibm.com>
		*
		* Derived from "crypto/aes_generic.c"
		*
		@@ -22,20 +24,25 @@

		#include <crypto/aes.h>
		#include <crypto/algapi.h>
		#include <crypto/ghash.h>
		#include <crypto/internal/aead.h>
		#include <crypto/internal/skcipher.h>
		#include <crypto/scatterwalk.h>
		#include <linux/err.h>
		#include <linux/module.h>
		#include <linux/cpufeature.h>
		#include <linux/init.h>
		#include <linux/spinlock.h>
		#include <linux/fips.h>
		#include <linux/string.h>
		#include <crypto/xts.h>
		#include <asm/cpacf.h>

		static u8 *ctrblk;
		static DEFINE_SPINLOCK(ctrblk_lock);

		static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
		static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
		kma_functions;

		struct s390_aes_ctx {
		u8 key[AES_MAX_KEY_SIZE];
		@@ -55,6 +62,17 @@ struct s390_xts_ctx {
		struct crypto_skcipher *fallback;
		};

		struct gcm_sg_walk {
		struct scatter_walk walk;
		unsigned int walk_bytes;
		u8 *walk_ptr;
		unsigned int walk_bytes_remain;
		u8 buf[AES_BLOCK_SIZE];
		unsigned int buf_bytes;
		u8 *ptr;
		unsigned int nbytes;
		};

		static int setkey_fallback_cip(struct crypto_tfm tfm, const u8 in_key,
		unsigned int key_len)
		{
		@@ -771,6 +789,267 @@ static struct crypto_alg ctr_aes_alg = {
		}
		};

		static int gcm_aes_setkey(struct crypto_aead tfm, const u8 key,
		unsigned int keylen)
		{
		struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);

		switch (keylen) {
		case AES_KEYSIZE_128:
		ctx->fc = CPACF_KMA_GCM_AES_128;
		break;
		case AES_KEYSIZE_192:
		ctx->fc = CPACF_KMA_GCM_AES_192;
		break;
		case AES_KEYSIZE_256:
		ctx->fc = CPACF_KMA_GCM_AES_256;
		break;
		default:
		return -EINVAL;
		}

		memcpy(ctx->key, key, keylen);
		ctx->key_len = keylen;
		return 0;
		}

		static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
		{
		switch (authsize) {
		case 4:
		case 8:
		case 12:
		case 13:
		case 14:
		case 15:
		case 16:
		break;
		default:
		return -EINVAL;
		}

		return 0;
		}

		static void gcm_sg_walk_start(struct gcm_sg_walk gw, struct scatterlist sg,
		unsigned int len)
		{
		memset(gw, 0, sizeof(*gw));
		gw->walk_bytes_remain = len;
		scatterwalk_start(&gw->walk, sg);
		}

		static int gcm_sg_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
		{
		int n;

		/* minbytesneeded <= AES_BLOCK_SIZE */
		if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
		gw->ptr = gw->buf;
		gw->nbytes = gw->buf_bytes;
		goto out;
		}

		if (gw->walk_bytes_remain == 0) {
		gw->ptr = NULL;
		gw->nbytes = 0;
		goto out;
		}

		gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
		if (!gw->walk_bytes) {
		scatterwalk_start(&gw->walk, sg_next(gw->walk.sg));
		gw->walk_bytes = scatterwalk_clamp(&gw->walk,
		gw->walk_bytes_remain);
		}
		gw->walk_ptr = scatterwalk_map(&gw->walk);

		if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
		gw->ptr = gw->walk_ptr;
		gw->nbytes = gw->walk_bytes;
		goto out;
		}

		while (1) {
		n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
		memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
		gw->buf_bytes += n;
		gw->walk_bytes_remain -= n;
		scatterwalk_unmap(&gw->walk);
		scatterwalk_advance(&gw->walk, n);
		scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);

		if (gw->buf_bytes >= minbytesneeded) {
		gw->ptr = gw->buf;
		gw->nbytes = gw->buf_bytes;
		goto out;
		}

		gw->walk_bytes = scatterwalk_clamp(&gw->walk,
		gw->walk_bytes_remain);
		if (!gw->walk_bytes) {
		scatterwalk_start(&gw->walk, sg_next(gw->walk.sg));
		gw->walk_bytes = scatterwalk_clamp(&gw->walk,
		gw->walk_bytes_remain);
		}
		gw->walk_ptr = scatterwalk_map(&gw->walk);
		}

		out:
		return gw->nbytes;
		}

		static void gcm_sg_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
		{
		int n;

		if (gw->ptr == NULL)
		return;

		if (gw->ptr == gw->buf) {
		n = gw->buf_bytes - bytesdone;
		if (n > 0) {
		memmove(gw->buf, gw->buf + bytesdone, n);
		gw->buf_bytes -= n;
		} else
		gw->buf_bytes = 0;
		} else {
		gw->walk_bytes_remain -= bytesdone;
		scatterwalk_unmap(&gw->walk);
		scatterwalk_advance(&gw->walk, bytesdone);
		scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
		}
		}

		static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
		{
		struct crypto_aead *tfm = crypto_aead_reqtfm(req);
		struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
		unsigned int ivsize = crypto_aead_ivsize(tfm);
		unsigned int taglen = crypto_aead_authsize(tfm);
		unsigned int aadlen = req->assoclen;
		unsigned int pclen = req->cryptlen;
		int ret = 0;

		unsigned int len, in_bytes, out_bytes,
		min_bytes, bytes, aad_bytes, pc_bytes;
		struct gcm_sg_walk gw_in, gw_out;
		u8 tag[GHASH_DIGEST_SIZE];

		struct {
		u32 _[3]; /* reserved */
		u32 cv; /* Counter Value */
		u8 t[GHASH_DIGEST_SIZE];/* Tag */
		u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */
		u64 taadl; /* Total AAD Length */
		u64 tpcl; /* Total Plain-/Cipher-text Length */
		u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
		u8 k[AES_MAX_KEY_SIZE]; /* Key */
		} param;

		/*
		* encrypt
		* req->src: aad\|\|plaintext
		* req->dst: aad\|\|ciphertext\|\|tag
		* decrypt
		* req->src: aad\|\|ciphertext\|\|tag
		* req->dst: aad\|\|plaintext, return 0 or -EBADMSG
		* aad, plaintext and ciphertext may be empty.
		*/
		if (flags & CPACF_DECRYPT)
		pclen -= taglen;
		len = aadlen + pclen;

		memset(&param, 0, sizeof(param));
		param.cv = 1;
		param.taadl = aadlen * 8;
		param.tpcl = pclen * 8;
		memcpy(param.j0, req->iv, ivsize);
		(u32 )(param.j0 + ivsize) = 1;
		memcpy(param.k, ctx->key, ctx->key_len);

		gcm_sg_walk_start(&gw_in, req->src, len);
		gcm_sg_walk_start(&gw_out, req->dst, len);

		do {
		min_bytes = min_t(unsigned int,
		aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
		in_bytes = gcm_sg_walk_go(&gw_in, min_bytes);
		out_bytes = gcm_sg_walk_go(&gw_out, min_bytes);
		bytes = min(in_bytes, out_bytes);

		if (aadlen + pclen <= bytes) {
		aad_bytes = aadlen;
		pc_bytes = pclen;
		flags \|= CPACF_KMA_LAAD \| CPACF_KMA_LPC;
		} else {
		if (aadlen <= bytes) {
		aad_bytes = aadlen;
		pc_bytes = (bytes - aadlen) &
		~(AES_BLOCK_SIZE - 1);
		flags \|= CPACF_KMA_LAAD;
		} else {
		aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
		pc_bytes = 0;
		}
		}

		if (aad_bytes > 0)
		memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);

		cpacf_kma(ctx->fc \| flags, &param,
		gw_out.ptr + aad_bytes,
		gw_in.ptr + aad_bytes, pc_bytes,
		gw_in.ptr, aad_bytes);

		gcm_sg_walk_done(&gw_in, aad_bytes + pc_bytes);
		gcm_sg_walk_done(&gw_out, aad_bytes + pc_bytes);
		aadlen -= aad_bytes;
		pclen -= pc_bytes;
		} while (aadlen + pclen > 0);

		if (flags & CPACF_DECRYPT) {
		scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
		if (crypto_memneq(tag, param.t, taglen))
		ret = -EBADMSG;
		} else
		scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);

		memzero_explicit(&param, sizeof(param));
		return ret;
		}

		static int gcm_aes_encrypt(struct aead_request *req)
		{
		return gcm_aes_crypt(req, CPACF_ENCRYPT);
		}

		static int gcm_aes_decrypt(struct aead_request *req)
		{
		return gcm_aes_crypt(req, CPACF_DECRYPT);
		}

		static struct aead_alg gcm_aes_aead = {
		.setkey = gcm_aes_setkey,
		.setauthsize = gcm_aes_setauthsize,
		.encrypt = gcm_aes_encrypt,
		.decrypt = gcm_aes_decrypt,

		.ivsize = GHASH_BLOCK_SIZE - sizeof(u32),
		.maxauthsize = GHASH_DIGEST_SIZE,
		.chunksize = AES_BLOCK_SIZE,

		.base = {
		.cra_flags = CRYPTO_ALG_TYPE_AEAD,
		.cra_blocksize = 1,
		.cra_ctxsize = sizeof(struct s390_aes_ctx),
		.cra_priority = 900,
		.cra_name = "gcm(aes)",
		.cra_driver_name = "gcm-aes-s390",
		.cra_module = THIS_MODULE,
		},
		};

		static struct crypto_alg *aes_s390_algs_ptr[5];
		static int aes_s390_algs_num;

		@@ -790,16 +1069,19 @@ static void aes_s390_fini(void)
		crypto_unregister_alg(aes_s390_algs_ptr[aes_s390_algs_num]);
		if (ctrblk)
		free_page((unsigned long) ctrblk);

		crypto_unregister_aead(&gcm_aes_aead);
		}

		static int __init aes_s390_init(void)
		{
		int ret;

		/* Query available functions for KM, KMC and KMCTR */
		/* Query available functions for KM, KMC, KMCTR and KMA */
		cpacf_query(CPACF_KM, &km_functions);
		cpacf_query(CPACF_KMC, &kmc_functions);
		cpacf_query(CPACF_KMCTR, &kmctr_functions);
		cpacf_query(CPACF_KMA, &kma_functions);

		if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) \|\|
		cpacf_test_func(&km_functions, CPACF_KM_AES_192) \|\|
		@@ -840,6 +1122,14 @@ static int __init aes_s390_init(void)
		goto out_err;
		}

		if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) \|\|
		cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) \|\|
		cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
		ret = crypto_register_aead(&gcm_aes_aead);
		if (ret)
		goto out_err;
		}

		return 0;
		out_err:
		aes_s390_fini();